Light emitting diode package having a voltage stabilizing module consisting of two doping layers

ABSTRACT

A light emitting diode package includes an electrically insulated base, first and second electrodes, an LED chip, a voltage stabilizing module, and an encapsulative layer. The base has a first surface and an opposite second surface. The first and second electrodes are formed on the first surface of the base. The LED chip is electrically connected to the first and second electrodes. The voltage stabilizing module is formed on the first surface of the base, positioned between and electrically connected to the first and second electrodes. The voltage stabilizing module connects to the LED chip in reverse parallel and has a polarity arranged opposite to that of the LED chip. The voltage stabilizing module has an annular shape and encircles the first electrode. The encapsulative layer is formed on the base and covers the LED chip.

BACKGROUND

1. Technical Field

The present disclosure relates to semiconductor devices and, moreparticularly, to a light emitting diode (LED) package and a method formanufacturing the LED.

2. Description of Related Art

LEDs have many beneficial characteristics, including low electricalpower consumption, low heat generation, long lifetime, small volume,good impact resistance, fast response and excellent stability. Thesecharacteristics have enabled the LEDs to be widely used as a lightsource in electrical appliances and electronic devices.

The LEDs are one-way conducting elements. If current flows through theLEDs in a forward direction, the LEDs emit light. If current flowsthrough the LEDs in a reverse direction, the LEDs fail to emit light. Inaddition, the LEDs would be broken down if the reverse current is toolarge. There is unpredictable current, such that caused by staticelectricity, which may flow through the LEDs in the reverse directionduring the operation of the LEDs. A voltage stabilizing diode such as aZener diode, is therefore applied to the LEDs for preventing the LEDsfrom damage by such unpredictable current in the reverse direction. Atypical design of the Zener diode is reverse parallel connecting theZener diode with the LEDs via wires and positioning the Zener diodeoutside of the package of the LEDs. The reverse parallel connectionmeans that the Zener diode is connected in parallel with LEDs while theZener diode is reverse biased and the LEDs are forward biased. Suchdesign has some deficiencies. For example, such a connection way resultsin a complicated structure, and a large volume of the LEDs. Moreimportantly, such a connection way may not obtain a stable electricalconnection between the Zener diode and the LEDs after the LEDs havingbeen use for a certain time.

What is needed is an LED package and a method for manufacturing the LEDpackage which can overcome the problem of the prior art.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a section view of an LED package in accordance with anexemplary embodiment of the present disclosure.

FIG. 2 is a top view of the LED package in accordance with the exemplaryembodiment of the present disclosure.

FIG. 3 shows a plurality of structures being made according to a flowchart of a method of manufacturing the LED package in accordance withthe exemplary embodiment of the present disclosure.

DETAILED DESCRIPTION

Referring to FIGS. 1 and 2, a light emitting diode (LED) package inaccordance with an exemplary embodiment of the present disclosurecomprises an electrically insulated base 100, two LED chips 11, avoltage stabilizing module 12, a first electrode 131, a second electrode132, and an encapsulative layer 14. The voltage stabilizing module 12 isformed on the base 100 and electrically connects to the first and secondelectrodes 131, 132. The LED chips 11 are mounted on the first electrode131 and electrically connect to the first and second electrodes 131,132. When the first and second electrodes 131, 132 electrically connectto a power source (not shown), the LED chips 11 have forward currentflowing therethrough and emit light. The voltage stabilizing module 12has a polarity arranged opposite to that of each of the LED chips 11.Thus, the irregular current or static electricity, if there is anyduring the operation of the LED chips 11, can be discharged by thevoltage stabilizing module 12, and the LED chips 11 are prevented fromdamage. In the preferred embodiment, the first electrode 131 isconnected to the positive pole of the power source, while the secondelectrode 132 is connected to the negative pole of the power source,whereby the forward current can flow through the LED chips 11 to causethe LED chips 11 to emit light.

Specifically, the base 100 has a first surface 101 and a second surface102 opposite to the first surface 101. A protrusion 103 extends upwardlyand annularly from the first surface 101. The protrusion 103 can beformed by patternizing the first surface 101 via microlithography andetching. The base 100 may be made of the following one or more than oneof the materials: Si, GaAs, ZnO and InP.

The voltage stabilizing module 12 can be formed by doping the protrusion103 of the base 100 to convert the protrusion 103 into the voltagestabilizing module 12. The doping can by any type such as epitaxialdope, diffusing dope or ion-implantation. It is understood that thevoltage stabilizing module 12 can be formed on the surface of theprotrusion 103. The voltage stabilizing module 12 comprises a firstdoping layer 121 and a second doping layer 122. The first doping layer121 is located beside the second doping layer 122. The first dopinglayer 121 and the second doping layer 122 have an identical thickness,and are in the same level. The first doping layer 121 is a P-type dopinglayer, and the second doping layer 122 is an N-type doping layer.

The first electrode 131 is positioned on a center portion of the firstsurface 101 of the base 100. The first electrode 131 has a rectangularshape. The first electrode 131 is encircled by the voltage stabilizingmodule 12. Specifically, the second doping layer 122 encircles and isattached to the first electrode 131, and the first doping layer 121encircles and is attached to the second doping layer 122. The secondelectrode 132 encircles and is attached to the first doping layer 121.The voltage stabilizing module 12 is such configured to electricallyconnect the first and second electrodes 131, 132, whereby whenconnecting with the power source, the LED chips 11 emit light, and thevoltage stabilizing module 12 discharges the irregular current or staticelectricity. The second electrode 132 is formed on the first surface 101of the base 100 and bends and extends to the second surface 102 of thebase 100. The first electrode 131 can also penetrate through the base100 and extend to the second surface 102 of the base 100; thus, the LEDpackage can be formed as a surface mounting device.

Each of the LED chips 11 has two poles, i.e., anode pole 111 and cathodepole 112. The poles 111, 112 are electrically connected to the first andsecond electrodes 131, 132 respectively via metal wires (not labeled).The LED chips 11 can be only one, or can be more than two in analternative embodiment. When connecting with the power source, thecurrent of the power source is flown through the LED chips 11 foremitting light, while the irregular current or static electricity can bedischarged by the voltage stabilizing module 12.

The encapsulative layer 14 is made of transparent or translucentmaterials. The encapsulative layer 14 is formed on the base 100 andencapsulates the LED chips 11. Phosphors can be contained in theencapsulative layer 14.

Compared with the conventional package structure, the LED package of thepresent disclosure provides the voltage stabilizing module 12 in anannular shape and in a position between the first and second electrodes131, 132, the thickness and indeed the volume of the LED package istherefore decreased. Simultaneously, the annular voltage stabilizingmodule 12 positioned between the first and second electrodes 131, 132ensures a stable connection therebetween; thus, the object of preventingthe LED package from breaking down such as via static electricity isachieved. Furthermore, the LED package in accordance with the presentdisclosure is more durable and reliable.

Furthermore, the LED package can be formed as a surface mounting devicethanks to the base 100 being formed of nonconductive materials, i.e.,being insulated, and there is no need to form an insulating material onthe base 100.

A method of manufacturing the LED package of the present disclosure nowwill be described in detail hereinafter with reference to FIG. 3.

First, an electrically insulated base 100 is provided. The base 100 maybe made of the following one or more than one of the materials: Si,GaAs, ZnO and InP. The base 100 has a first surface 101 and a secondsurface 102 opposite to the first surface 101. A protrusion 103 isextended upwardly and annularly from the first surface 101 bypatternizing the first surface 101 via etching or microlithography.

Second, a first doping layer 121 and a second doping layer 122 areformed in the protrusion 103 by doping the protrusion 103 with twodifferent elements or two types of different elements. An annularvoltage stabilizing module 12 is thus formed and in the shape of theprotrusion 103. The type of doping can be epitaxial doping or ironimplantation. The first doping layer 121 is a P-type doping layer, andthe second doping layer 122 is an N-type doping layer. The first dopinglayer 121 and the second doping layer 122 are arranged side by side. Thefirst and second doping layers 121, 122 are positioned in a same leveland have an identical thickness.

Third, a first electrode 131 is formed on a center portion of the firstsurface 101 of the base 100. The first electrode 131 is encircled by andattached to the second doping layer 122 of the voltage stabilizingmodule 12. The first electrode 131 penetrates through the base 100 andextends to the second surface 102 of the base 100. A second electrode132 is formed on a periphery portion of the first surface 101 of thebase 100. The second electrode 132 encircles and is attached to thefirst doping layer 121 of the voltage stabilizing module 12. The secondelectrode 132 bends and extends to the second surface 102 of the base100. The first electrode 131 and the second electrode 132 areelectrically insulated from each other on the second surface 102 of thebase 100.

Fourth, two LED chips 11 are mounted on the first electrode 131. The LEDchips 11 are electrically connected to the first and second electrodes131, 132 via wire bonding. The voltage stabilizing module 12 connects tothe LED chips 11 in reverse parallel. The voltage stabilizing module 12has a polarity opposite to that of the LED chips 11; that is, whenconnecting a power source to the LED package, the anode of the powersource connects to the anode pole 111 of the LED chip 11 via the firstelectrode 131, which connects with a P-type semiconductor layer of theLED chip 11, while the anode of the power source connects to the seconddoping layer 122 of the voltage stabilizing module 12 via the firstelectrode 131, which is an N-type doping layer (i.e., an N-typesemiconductor layer).

At last, an encapsulative layer 14 is formed on the base 100 and coversthe LED chips 11. The encapsulative layer 14 is made of transparent ortranslucent materials. Phosphors can be contained in the encapsulativelayer 14.

It is to be understood, however, that even though numerouscharacteristics and advantages of the embodiments have been set forth inthe foregoing description, together with details of the structures andfunctions of the embodiments, the disclosure is illustrative only, andchanges may be made in detail, especially in matters of shape, size, andarrangement of parts within the principles of the disclosure to the fullextent indicated by the broad general meaning of the terms in which theappended claims are expressed.

What is claimed is:
 1. An LED (light emitting diode) package comprising:an electrically insulated base, the base having a first surface and asecond surface opposite to the first surface; a first electrode formedon the first surface of the base; a second electrode formed on the firstsurface of the base; at least one LED chip formed on the first electrodeand electrically connected to the first and second electrodes; a voltagestabilizing module formed on the first surface of the base, the voltagestabilizing module being positioned between and electrically connectedto the first and the second electrodes, the voltage stabilizing moduleconnecting to the at least one LED chip in reverse parallel and having apolarity arranged opposite to that of the at least one LED chip, and thevoltage stabilizing module having an annular shape and encircling thefirst electrode; and an encapsulative layer formed on the base andcovering the at least one LED chip; wherein the voltage stabilizingmodule comprises a first doping layer and a second doping layer attachedto the first doping layer, the second doping layer being attached to andencircling the first electrode.
 2. The LED package of claim 1, whereinthe first and second doping layers are in the same level and have anidentical thickness.
 3. The LED package of claim 1, wherein the secondelectrode is attached to and encircles the first doping layer.
 4. TheLED package of claim 1, wherein the second electrode bends and extendsto the second surface of the base.
 5. The LED package of claim 4,wherein the first electrode penetrates through and extends to the secondsurface of the base, the first and second electrodes are electricallyinsulated from each other on the second surface of the base.
 6. The LEDpackage of claim 1, wherein an annular protrusion is formed on the firstsurface of the base, and the voltage stabilizing module is formed by theprotrusion.
 7. The LED package of claim 1, wherein the base is made ofthe following one or more than one of the materials: Si, GaAs, ZnO andInP.
 8. An LED (light emitting diode) package comprising: anelectrically insulated base, the base having a first surface and asecond surface opposite to the first surface; a first electrode formedon the first surface of the base; a second electrode formed on the firstsurface of the base; at least one LED chip formed on the first electrodeand electrically connected to the first and second electrodes; a voltagestabilizing module formed on the first surface of the base, the voltagestabilizing module being positioned between and electrically connectedto the first and the second electrodes, the voltage stabilizing moduleconnecting to the at least one LED chip in reverse parallel and having apolarity arranged opposite to that of the at least one LED chip, and thevoltage stabilizing module having an annular shape and encircling thefirst electrode; and an encapsulative layer formed on the base andcovering the at least one LED chip; wherein the second electrode bendsand extends to the second surface of the base.
 9. The LED package ofclaim 8, wherein the first electrode penetrates through and extends tothe second surface of the base, the first and second electrodes areelectrically insulated from each other on the second surface of thebase.
 10. The LED package of claim 8, wherein an annular protrusion isformed on the first surface of the base, and the voltage stabilizingmodule is formed by the protrusion.
 11. The LED package of claim 8,wherein the base is made of the following one or more than one of thematerials: Si, GaAs, ZnO and InP.